Deductions & credits

Okay, so if I understand you correctly, I don't do anything on my tax return for 2020.  I wait until 2021 to add the asset as a rental.  Is this correct?

 

What do I do about the 2020 expenses on my new property that I bought and began to rehab (buy materials, pay contractors, pay utilities, pay property tax, etc.) ?  Do I wait until 2021 and put in all the expenses (both for 2020 and 2021 (i.e. carry expenses forward?)

 

...or do I add in the 2020 expenses now and if so, where do I put them if I don't add the asset to my return because if did not go into service yet?